Patents Assigned to Xronet Corporation
  • Patent number: 8457238
    Abstract: A soft decision decoding method in a multiple-input multiple-output system which respectively receives two simultaneously transmitted data streams, a first transmitting symbol and a second transmitting symbol, in a first receiving signal and a second receiving signal is provided.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: June 4, 2013
    Assignee: Xronet Corporation
    Inventors: Seung hyuk Ahn, Hyung won Kim
  • Patent number: 8254434
    Abstract: In a method for estimating a signal-to-noise ratio (SNR) of an orthogonal frequency division multiplexing (OFDM) wireless mobile communication system, noise is estimated from adjacent received signals of at least two adjacent subcarriers and received signals of subcarriers, noise power is calculated by calculating a mean square value of the estimated noise by summing squares of the estimated noise, a mean square value of the received signals is calculated by summing squares of the received signals, signal power is calculated by subtracting the noise power from the mean square value of the received signals, and the SNR is calculated using the signal power and the noise power. Thus, the method of the present invention having low complexity can estimate an SNR efficiently regardless of channel changes on a frequency axis when one OFDM symbol includes preamble data.
    Type: Grant
    Filed: November 29, 2007
    Date of Patent: August 28, 2012
    Assignee: XRONet Corporation
    Inventor: Keun-Moo Lee
  • Patent number: 8223868
    Abstract: A method of determining a variable quantization step size is disclosed. In the method of determining a variable quantization step size, a channel characteristic parameter is obtained in order to calculate a quantization step size (?) used in channel decoding. The quantization step size (?) is variably determined based on the channel characteristic parameter. Therefore, the method of determining a variable quantization step size may improve channel decoding.
    Type: Grant
    Filed: May 17, 2007
    Date of Patent: July 17, 2012
    Assignee: XRONet Corporation
    Inventor: Keun-Moo Lee
  • Patent number: 7944286
    Abstract: A filter tuning system for quickly compensating a time constant using a binary search algorithm is disclosed. The filter tuning system includes a time constant detector, a comparator and a calibration unit. The time constant detector detects a time constant of a filter based on an integral value of a reference input signal using an integrator when the time constant of the filter changes according to a variation of a manufacturing process or a temperature. The integrator includes a capacitor changing according to a variation of the time constant of the filter. The comparator compares the detected time constant with a reference value. The calibration unit compensates the time constant of the filter using the binary search algorithm based on the comparison result until an error between the time constant and the reference value is reduced within an acceptable range.
    Type: Grant
    Filed: November 30, 2007
    Date of Patent: May 17, 2011
    Assignee: XRONET Corporation
    Inventor: Jung-Hoon Yoo
  • Patent number: 7936213
    Abstract: A Doherty amplifier is provided. The Doherty amplifier includes a first path circuit including a carrier amplifier and a first impedance adjusting circuit connected with the carrier amplifier; and a second path circuit including a peaking amplifier, a second impedance adjusting circuit connected with the peaking amplifier, and a peaking amplifier bias circuit connected with the peaking amplifier. At least one among an impedance of the first impedance adjusting circuit, an impedance of the second impedance adjusting circuit, and a bias of the peaking amplifier bias circuit is adjusted in response to a control signal.
    Type: Grant
    Filed: August 24, 2009
    Date of Patent: May 3, 2011
    Assignee: Xronet Corporation
    Inventors: Jin Ho Shin, Ki Chon Han